Her supporters in court, including national lawmakers, squabbled with riot police, trying to prevent them from driving her away in a prison car and shouting: “Shame! Shame!’’

Dozens of Tymoshenko’s supporters then gathered outside the court building in central Kiev and tried to block the road.

The United States and the European Union have condemned court cases against Tymoshenko and several of her top allies as selective prosecution of political opponents. Germany expressed “great concern’’ yesterday about Tymoshenko’s arrest.

Viktor Yanukovych, Ukraine’s Kremlin-friendly president, has been accused by opposition activists and rights groups of trying to sideline his political opponents and muzzle critical media in a rollback on freedoms championed by his predecessor.

Tymoshenko, the country’s top opposition leader, has criticized the trial as an attempt by Yanukovych to bar her from elections and mocked the court.

Complying with the judge’s orders, police surrounded Tymoshenko and escorted her out of the courtroom yesterday. Hundreds of police officers swarmed the prison car as it forced its way slowly through the crowd.

Later, Tymoshenko’s ally, Serhiy Vlasenko, showed reporters what he called a handwritten note from her describing her arrest as a “political repression.’’

The 50-year-old opposition leader is charged with abusing her powers by signing a natural gas import contract with Russia in 2009 that prosecutors claim was disadvantageous to Ukraine.

Tymoshenko insists she is innocent, arguing that the contract ended weeks of natural gas disruptions to Ukrainian and European consumers and that she was authorized to sign the deal as prime minister.

Yesterday, Tymoshenko was put in the same jail where one of her allies, former interior minister Yuri Lutsenko, has been held for more than six months on charges that he defrauded the government.

Analysts in Ukraine and abroad believe the real motive for Tymoshenko’s trial is to disqualify her from upcoming elections by convicting her as a felon.

Tymoshenko was nicknamed Ukraine’s “gas princess’’ in the late 1990s for serving as the head of a leading natural gas importer. She was jailed briefly in 2001 on suspicion of smuggling gas, but the case never went to trial.

Tymoshenko has a long and bitter history with Yanukovych.

She was the central figure in Ukraine’s 2004 Orange Revolution mass protests that threw out Yanukovych’s fraud-tainted victory in a presidential election and led to another vote that brought a pro-Western government to power.